How is natural selection supposed to thus select on the basis of a hoped-for functionality, rather than simply do a random walk around some starting point for such a potential?

Evolution doesn't require selection on the basis of future need. Darwin's proposition is that existing structures would be pressed into novel uses, and would be improved to suit new needs. For example, the ear bones in mammals that amplify sounds in the middle ear were not initially selected on the basis of their acoustic properties, but rather were jaw bones in the propsed ancestral line.

Jaw bones already have acoustic properties, (as well as other reasons for the whole reptile/mammal transition), and thus selecting bone properties based on their acoustics is not a case of selection of a future utility, it is improving a current one. In fact, a lot of effort is spent by evolutionary theorists to model how features used for one purpose could be used for other purposes, and thus be subjects to selection pressures that would change them. This concept is applied everywhere, and is a central concept in evolutionary theory, and has been since Darwin.

Thus the claim that natural selection ... more.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.